1. Field of the Invention
The present invention relates to a microscope system which displays a high-resolution image of a wide angle of view.
2. Description of the Related Art
The need for computerization is growing rapidly also in the field of pathological diagnostics by microscopic observation.
For example, Japanese Patent Application Laid-open No. Hei 9-281405 has disclosed a virtual microscope system for reconstructing an image of an observation object by first dividing an entire observation object into small areas, capturing the divided areas using a high-resolution objective lens, and then combining the images obtained by the capturing operations.
In this system, a microscopic observation can be performed on an observation object without having an observation object at a spot so that the following observation (virtual microscopic observation) can be realized by image processing as well as an observation of an observation object actually at the spot.
1. Switch from Low-magnification Observation to High-Magnification Observation
In performing a low-magnification observation, an image of a wide angle of view can be displayed under reduction by combining a number of divided images while each of the divided images can be displayed as is in a high-magnification observation.
2. In an X-Y Operation to Observation Object
In an X-Y operation by a diagnostician, that is, in an operation of a diagnostician with an observation object traversed in a direction perpendicular to the optical path of a microscope, an observation object image is traversed in an X-Y movement by changing the display range of a reconstructed image.
In the system using the above-mentioned technology, an observation object can be diagnosed without restrictions of time. With the image data of an observation object image shared, a plurality of diagnosticians can simultaneously observe the same observation object in the respective locations. In addition, a diagnostician can make an observation anywhere.
When an observation is performed in the X-Y operation using a real observation object, the possible out-of-focus state due to the inclination, etc. of the object normally has to be corrected. However, in this system, an object can be observed constantly in an in-focus state. Therefore, a diagnosis can be carried out with high reliability and efficiency.
Additionally, in the field of training of pathological diagnosticians using a real observation object, the same observation objects are to be prepared for the pathological diagnosticians. However, in the present system, the same observation object images can be used in the training by taking advantage of sharing image data of an observation object image.
Furthermore, using a preparation containing a real observation object, the same samples cannot be prepared in the same state when the observation object becomes faded of damaged. However, using an observation object image represented by electronic data, backup data can be used in observations in the same state anytime and anywhere.
As described above, the microscope system disclosed by Japanese Patent Application Laid-open No. Hei 9-281405 enables an efficient observation to be realized in a microscopic observation on a real observation object with high precision and reliability.
A similar technology is also disclosed by, for example, Japanese Patent Application Laid-open No. Hei 5-333271.
For another example, Japanese Patent Application Laid-open No. 2002-258163 has disclosed a remote microscopic observation system for determining a traverse pitch of a focal position in obtaining a microscopic image in a plurality of focal positions based on the optical wavelength used in a sample observation and the numerical aperture of an objective lens used in a sample observation, storing in an image database the microscopic image obtained with the focal position moved based on the determined traverse pitch, and distributing and displaying the microscopic image at a request from each of a plurality of personal computers.
Japanese Patent Application Laid-open No. Hei 9-298682 (U.S. Pat. No. 5,933,513) discloses the technology of a depth of focus extension apparatus capable of obtaining at a lower cost an image of a long depth of focus and constantly excellent in resolution and brightness in optically variable conditions of the numerical aperture, the available wavelength of an image pickup device, etc. of an image forming optical system, based on the technology (refer to, for example, Japanese Patent Publication No. 3191928) of recovering an image of an object in different locations in the optical axis direction by performing a recovery process using a spatial frequency filter referred as a recovery filter on a summed image obtained by adding up a plurality of images including an image in an in-focus state of an object in different locations in the optical axis direction.
In the conventional virtual microscope system, there is the problem that the information in the Z direction, that is, in the optical axis direction of a microscope, can be lost due to the thickness of an observation object.
FIG. 1 shows an example of the relationship between an observation object and the depth of focus of an objective lens. When there are two cells A and B in an observation object having the thickness of α, the object is captured by an objective lens having the depth of focus of β.
In the status as shown in FIG. 1, the cells A and B cannot be simultaneously captured using the depth of focus of β, and either the cell A or B cannot appear on the captured image. Additionally, although the cells A and B are located closer to each other in the thickness direction, one of the cells A and B can be set in an in-focus state with the other in an out-of-focus state, thereby obtaining a resultant observation object image with a part of the information lost.
If a real observation object is used in a microscopic observation, the depth of focus can be increased by performing a low-magnification observation using a low magnification objective lens, thereby carrying out the observation with both two cells in the in-focus state.
However, in an observation using the virtual microscope system according to the conventional technology, the observation cannot be performed with both two cells simultaneously in-focus state although the image processing is performed with divided and captured images combined into a reconstructed image in a low-magnification observation.